A newly discovered vulnerability in text messaging may enable attackers to trace your location, according to Northeastern Ph.D. student Evangelos Bitsikas.
The hotspot would have its own sim card not the one that was in your phone. The one in your phone was removed in this case. The number of the hotspot is not known to the attacker and the phone can still be used for calls and texts via signal or WhatsApp or whatever
A mobile hotspot is effectively just a mobile without a screen. It would only provide protection from this exploit if sms was fully disabled
The hotspot would have its own sim card not the one that was in your phone. The one in your phone was removed in this case. The number of the hotspot is not known to the attacker and the phone can still be used for calls and texts via signal or WhatsApp or whatever